aslangroudi
Posts: 10
Joined: Fri Jul 14, 2017 6:16 pm
Delivery Date: 31 Jul 2017

Help on LeafSpy Data

Thu Aug 24, 2017 1:02 am

Hello, I bought a used leaf about a month ago and bought leafspy and am a newbie. I'm confused/lost/read conflicting info on interpreting leaf battery data even when I tried reading/searching for answers (many posts about stats but few on interpreting). In the best link I found...viewtopic.php?f=6&t=21919...I've read that Ahr and SOH are the only two stats a moderator would look at and elsewhere an experienced poster said Hx is almost the perfect stat for % of original capacity. Gids? DTE? Is there any kind of guide that shows what every stat/graph means? After driving the car just for a few minutes I got a pretty big difference in SOH stat 94.2% to 80%. Any advice/help is greatly appreciated. I guess I'm not experienced enough of poster to post an image of my leafspy stats so I will list them for my 2014 Leaf with 29010 miles and 11 bars:
At full charge on the main page:
SOH: 94.2%
Hx: 78.4%
221 GIDs

After only two miles driving on the page with Bat Sts and the chart:
SOH: 80%
Hx: 74.35%
AHr: 52.76
And ALL red bars except one on the 10mV chart.

SageBrush
Posts: 1415
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Help on LeafSpy Data

Thu Aug 24, 2017 5:16 am

The 94.2 SOH reading is an artefact.
Everything else points to you having about 80% of new capacity.

To answer your other question ... somewhat:
Cell voltage and Ahr in/out are measured directly;
The car also keeps track of total charges, total DCFC use, and excursions into a high battery temperature range.

The GID, Hx and SOH are derived values that attempt to correct for unusual use history, but as you can see in your data they track with the simpler and more straightforward Ahr reading. So just follow Ahr; or if you want a little more accurate reading charge to full and calculate kWh capacity. That will be

Ahr*battery_voltage/1000
Brand new battery capacity is ~ 23 kWh or about 62 Ahr

Example:
I have the paid version of LeafSpy so it might not look identical to your version. I've circled the Ahr and battery voltage readings

Image


My kWh capacity at full charge then is 58.22*396.28/1000 = 23 kWh
After I drive a little the voltage drops to ~ 370 volts so a more accurate capacity is about 21 kWh
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

aslangroudi
Posts: 10
Joined: Fri Jul 14, 2017 6:16 pm
Delivery Date: 31 Jul 2017

Re: Help on LeafSpy Data

Thu Aug 24, 2017 7:59 am

Thanks so much for your reply! I do have pro version as well and my calculation comes to 391.77×52.76÷1000= 20.68. That's 90% of the 23, would that mean I'm at 90% of what my battery was when new? Or do you still think 80% based on other numbers? On the same bar graph I have all red but one (you have 2 blue). Red seems bad...is there a way to improve that?

SageBrush
Posts: 1415
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Help on LeafSpy Data

Thu Aug 24, 2017 8:39 am

Red is bad in politics but in LeafSpy it just means that battery cells are being rebalanced. Don't worry about it.

Figure average voltage from a SoC of 100% down to empty is about 370v, so your total usable energy is about
52.76*370/1000 = 19.5 kWh.

Since a new battery is ~ 23 kWh, you have 19.5/23 = 85% of new.

LeafSpy does not let you get more accurate than this, but it would match a car history of recently losing the 12th bar.
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

aslangroudi
Posts: 10
Joined: Fri Jul 14, 2017 6:16 pm
Delivery Date: 31 Jul 2017

Re: Help on LeafSpy Data

Thu Aug 24, 2017 9:17 am

:lol:
Awesome! Thanks sooo much for the help! I now feel a little better about taking that leap of faith in trusting the dealers data.

SageBrush
Posts: 1415
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: Help on LeafSpy Data

Thu Aug 24, 2017 11:33 am

aslangroudi wrote::lol:
Awesome! Thanks sooo much for the help! I now feel a little better about taking that leap of faith in trusting the dealers data.

Glad you feel better. Enjoy your LEAF, and in the future please *never* trust the car dealer :D
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

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